[0001] The present invention is directed to substituted chromans of the formula (I), depicted
below, which by inhibiting 5-lipoxygenase enzyme are useful in the prevention or treatment
of asthma, arthritis, psoriasis, ulcers, myocardial infarction, stroke and related
disease states in mammals. The present invention is also directed to pharmaceutical
compositions, and to a method of treatment.
[0002] Kreft et al., in U.S. Patent 4,661,596, describe compounds which are disubstituted
naphthalenes, dihydronaphthalenes or tetralins having the formula

wherein the dotted lines represent optional double bonds, R
a is 2-pyridyl, 2-quinolyl, 2-pyrazinyl, 2-quinoxalinyl, 2-thiazolyl, 2-benzothiazolyl,
2-oxazolyl, 2-benzoxazolyl, 1-alkyl-2-imidazolyl or 1-alkyl-2-benzimidazolyl and R
b is hydroxy, lower alkoxy, lower alkyl or perfluoro alkyl. These compounds inhibit
lipoxygenase enzyme and antagonize the effects of leukotriene D4, and so are useful
in the prevention and treatment of asthma.
[0003] Eggler et al., in copending International application PCT/US87/02745 filed October
19, 1987 have described similarly active compounds, including chromans of the formula

wherein R
X is substantially defined as above, R
2 is aryl or heteroaryl, X
a is, for example, oxygen or CH
2, and x
b is C=O or CHOH. The present compounds generally fail to block leukotriene D4 receptors
and so, in this respect, are differentiated from the compounds of Eggler et al., who
also report certain structurally related compounds as intermediates (for example,
compounds of the formula immediately above wherein R" is benzyl. Many of these intermediates
also find utility as intermediates in the present invention.
[0004] The chemical nomenclature employed herein generally follows that of "I.U.P.A.C. Nomenclature
of Organic Chemistry, 1979 Edition," Pergammon Press, New York, 1979.
[0005] The present invention is directed to compounds having the structural formula

wherein
X is CH2 or 0;
Y and Y1 are taken together and form a carbonyl group, or Y and Y' are taken separately, Y
is hydrogen and Y' is hydroxy or an acyloxy group which is hydrolyzed to form a hydroxy
group under physiological conditions;
R is attached by means of aromatic or heteroaromatic carbon and is phenyl, naphthyl,
pyridyl, quinolyl, isoquinolyl, pyridazinyl, cinnolinyl, phthalazinyl, pyrimidinyl,
naphthyridinyl, pyrrolyl, N-[(C1-C4)alkyl]pyrrolyl, indolyl, N-[(Ci-C4)alkyl]indolyl, isoindolyl, N-[(Ci-C4)alkyl]isoindolyl, indolizinyl, pyrazolyl, 1-[(C1-C4)alkyl]-pyrazolyl, indazolyl, 1-[(C1-C4)alkyl]-1H-indazolyl, 2-[(C1-C4)alkyl]-2H-indazolyl, imidazolyl, 1-[(C1-C4)alkyl]-imidazolyl, benzimidazolyl, 1-[(C1-C4)alkyl]benzimidazolyl, furyl, benzofuranyl, isobenzofuranyl, oxazolyl, benzoxazolyl,
isoxazolyl, benzo[c]isoxazolyl, benzo[d]isoxazolyi, thienyl, benzothiophenyl, isobenzothienyl,
thiazolyl, benzothiazolyl, isothiazolyl, benzo[c]isothiazolyl, or benzo[d]isothiazolyl;
or one of said groups which is mono- or disubstituted on carbon with the same or different
groups which are bromo, chloro, fluoro, hydroxy, hydroxymethyl, (Cl-C4)alkyl, (C1-C4)alkoxy, carboxy, [(C1-C4)alkoxy]carbonyl, or substituted on adjacent carbons with trimethylene, tetramethylene,
-CH2-0-CH2- or -O-CH2-O-; or substituted on tertiary nitrogen to form an N-oxide; and either, in a first
alternative,
RI is phenyl, 2-, 3- or 4-pyridyl, 2-, 3-, 4 or 8-quinolyl, 1-, 3- or 4-isoquinolyl,
3- or 4-pyridazinyl, 3- or 4- cinnolinyl, 1-phthalazinyl, 2-or 4-pyrimidinyl, 2- or
4-quinazolinyl, 2-pyrazinyl, 2-quinoxalinyl, 1-, 2- or 3- indolizinyl, 2-, 4- or 5-oxazolyl,
2-benzoxazolyl, 3-, 4- or 5-isoxazolyl, 5-benzo[c]isoxazolyl, 3-benzo[d]-isoxazolyl,
2-, 4- or 5-thiazolyl, 2-benzothiazolyl, 3-, 4- or 5-isothiazolyl, 5-benzo[c]isothiazolyl,
3-benzo[d]-isothiazolyl, 1-[(C,-C4)alkyl]-2-, 4- or 5-imidazolyl, 1-[(C1-C4)alkyl]-2-benzimidazolyl, 1-[(C1-C4)alkyl]-3-, 4-or 5-pyrazolyl, 2-[(C1-C4)alkyl]-3(2H)-indazolyl, or 1-[(C1-C4)alkyl]-3(1H)-indazolyl; or one of said groups mono- or disubstituted on carbon with
the same or different substituents which are bromo, chloro, fluoro, (C1-C4)alkyl, trifluoromethyl, hydroxy, hydroxymethyl or (C1-C4)alkoxy, or on adjacent carbons with trimethylene, tetramethylene, -CH2-0-CH2- or -0-CH2-0-; and
R2 is methyl, phenyl or phenyl mono- or disubstituted with the same or different substituents
which are bromo, chloro, fluoro, (C1-C4)alkyl, trifluoromethyl, hydroxy, hydroxymethyl or (C1-C4)alkoxy, or on adjacent carbons with trimethylene, tetramethylene, -CH2-0-CH2- or -0-CH2-0-; or, in a second alternative;
R' is 2-naphthyl or 2-naphthyl mono- or disubstituted with the same or different substituents
which are bromo, chloro, fluoro, (C1-C4)alkyl, trifluoromethyl, hydroxy, hydroxymethyl or (Cl-C4)alkoxy, or on adjacent carbons with trimethylene, tetramethylene, -CH2-0-CH2- or -0-CH2-0-; and
R2 is hydrogen, methyl, phenyl or phenyl mono- or disubstituted with the same or different
substituents which are bromo, chloro, fluoro, (Cl-C4)alkyl, trifluoromethyl, hydroxy, hydroxymethyl or (C1-C4)alkoxy, or on adjacent carbons with trimethylene, tetramethylene, -CH2-0-CH2- or -0-CH2-0-;
a pharmaceutically acceptable acid addition salt thereof when the compound contains
a basic amine function; or
a pharmaceutically acceptable cationic salt when the compound contains a carboxy group.
[0006] Because of their ease of preparation and valuable biological activity, the preferred
compounds of the formula (I) have R as either 3-pyridyl or 3-carboxyphenyl. When R
1 and R
2 are in the first alternative, the most preferred value of R
I is unsubstituted naphthyl and the most preferred value of R
2 is hydrogen. When R
1 and R
2 are in the second alternative, the preferred value of R
1 is 2-quinolyl and the preferred value of R
2 is methyl.
[0007] The bracket denotes attachment of the group R
1R
2CH-O- to either the C.6 or the C.7 position of the chroman ring. The more preferred
point of attachment is generally C.6.
[0008] When Y and Y' are taken separately the structural formula (I) represent both cis-
and trans-isomers, e.g., as follows:

and

[0009] The cis-isomers (II) are generally preferred over corresponding trans-isomers (III).
Fortunately, it is the preferred cis-isomer which usually predominates (sometimes
with virtual exclusion of the trans-isomer) in the synthetic methods employed in preparation
of the present compounds.
[0010] If desired, each of the isomers (II) and (III) can be resolved into a pair of optical
isomers, for example, by formation of diastereomeric esters by coupling the alcohol
with an optically active acid. Following conventional separation, e.g., fractional
crystallization or chromatography, the individual diastereomeric esters are hydrolyzed
to the pure, optically active enantiomers.
[0011] Said pharmaceutically-acceptable acid addition salts include, but are not limited
to, those with HCI, HBr, HN0
3, H
2SO
4, H
3PO
4, CH
3SO
3H, p-CH
3C
6H
4SO
3H, CH
3C0
2H, gluconic acid, tartaric acid, maleic acid and succinic acid. In the case of those
compounds of the formula (I) which contain a further basic nitrogen, it will, of course,
be possible to form diacid addition salts (e.g., the dihydrochloride) as well as the
usual monoacid addition salt. Said pharmaceutically-acceptable cationic salts include,
but are not limited to, those of sodium, potassium, calcium, magnesium, ammonia, N,N
-dibenzylethylenediamine, N-methylglucamine (meglumine), ethanolamine and diethanolamine.
[0012] The reference to Y' as an acyloxy group which is hydrolyzed to a hydroxy group under
physiological conditions refers to esters of a type which are frequently referred
to as "pro-drugs." Such esters are almost as well-known and common in the medicinal
art as pharmaceutically-acceptable salts. Such esters are generally used to enhance
oral absorption, but in any event are readily hydrolyzed in vivo to the parent hydroxy
compound. The more preferred acyloxy groups are those in which the acyl moiety is
the alpha-aminoacyl residue of a naturally occurring L-alpha-amino acid,

or

wherein
R3 and R4 are taken separately and are each independently hydrogen or (Cl-C4)alkyl, or R3 and R4 are taken together with the nitrogen to which they are attached to form a pyrrolidine,
piperidine, perhydroazepin or morpholine ring;
p is an integer from 1 to 4;
q is an integer from 1 to 3;
r is an integer from 2 to 3; and
s is an integer from 1 to 3.
[0013] Also forming a part of the present invention are pharmaceutical compositions for
administration to a mammal which comprise a compound of the formula (I) and a pharmaceutically
acceptable carrier; and a method of inhibiting 5-lipoxygenase enzyme in a mammal,
particularly in man, so as to prevent or treat asthma, arthritis, psoriasis, gastrointestinal
ulcers, stroke or myocardial infarction.
[0014] Of value in the present invention are intermediate compounds havina the structural
formula

wherein
in the first alternative
Y2 and Y3 are taken together and form a carbonyl group, or Y2 and Y3 are taken separately, Y2 is hydrogen and Y3 is hydroxy; and
Ra is hydroxy or benzyloxy;
Rb and Rc are taken separately, and Rb is hydrogen and R° is -X-R; and
X and R are as defined above;
or in the second alternative
Rb and Rc are taken together and are hydroxymethylene or diazo; or Rb and R° are taken separately, Rb is hydrogen and Rc is bromo; and
Ra is benzyloxy or

where RI and R2 are as defined above.
[0015] The present invention is readily carried out. Without regard to geometrical (cis-trans)
or optical isomers, the compounds of the formula (1) wherein Y + Y
1 = carbonyl, or Y = H and Y' = OH are prepared according to the chemical transformations
which are summarized in Flowsheets 1, 2 and 3, where the symbols R, R
1 and R
2 are as defined above. The various transformations found in these flowsheets, as well
as transformations required for the preparation of the compounds (I) having other
values of Y and Y', and methods for separation of cis-trans and optical isomers, are
detailed below.
[0016] The condensation of Flowsheet 1 is typically carried out with the phenolic group
in protected form as shown, methyl being a preferred protecting group only when X
is CH
2. The preferred conditions employ a molar excess of the required aldehyde and a molar
excess of a secondary amine such as pyrrolidine or piperidine as base. (It is understood
that such a base facilitates the condensation by forming an enamine intermediate.)
The reaction is generally carried out in a reaction-inert solvent, lower alcohols
such as methanol being particularly well suited for this purpose. The temperature
conditions for this transformation are not critical, e.g., 0-70° C is generally satisfactory,
with ambient temperature particularly well suited as a matter of convenience.
[0018] The C-alkylation of Flowsheet 1 is carried out by first converting the ketone (A)
to its lithium salt, usually in situ, by the action of substantially one molar equivalent
of a strong, sterically hindered base such as lithium diisopropylamide, usually carried
out at low temperature (e.g., about -40 to -80 C conveniently at the temperature of
a dry ice-acetone bath). The salt in turn is reacted with the alkylating agent, preferably
the highly reactive iodide, usually in molar excess in the presence of a molar excess
of hexamethyl phosphoramide, now at higher temperature (e.g., about 0 to 40° C). Conveniently,
the latter reagents are added to the cold lithium salt solution, and the temperature
allowed to rise to ambient temperature as the reaction proceeds. The salt preparation
and alkylation reaction are usually carried out in the same reaction-inert solvent
(e.g., tetrahydrofuran). It will be evident to those skilled in the art that any free
hydroxy or carboxy groups in the alkylating reagent should be in protected form (vide
supra).
[0019] The catalytic hydrogenation transformations (debenzylations, H
2-additions to double bond) of Flowsheets 1, 2 and 3 are carried out under conventional
conditions, generally in a reaction-inert solvent, and preferably using a noble metal
catalyst and moderate conditions of temperature (e.g., about 0 to 70° C) and hydrogen
pressure (e.g., about 1 to 10 atmospheres). While higher pressures may be desirable
in selected instances, such moderate pressures permit the use of much less elaborate
and expensive equipment. Suitable noble metal catalysts include platinum, palladium,
rhenium, rhodium and ruthenium, either of the supported or non-supported type, as
well as the known catalytic compounds thereof such as the oxides, chlorides, etc.
Examples of suitable catalyst supports include carbon, silica and barium sulfate.
[0020] The catalysts may be preformed or formed in situ by prereduction of an appropriate
salt of the catalytic compound. Examples of preferred catalysts are 5% palladium-on-carbon,
5% platinum-on-carbon; 5% rhodium-on-carbon, platinum chloride, palladium chloride,
platinum oxide and ruthenium oxide. Most preferred in the present instance is palladium-on-carbon.
Solvents generally suitable for the present hydrogenation include lower alkanols,
ethyl acetate and tetrahydrofuran.
[0021] The methyl ethers [compounds of the formula (C)] in Flowsheet 1 are deblocked to
form the corresponding phenol derivative, again, by conventional methods; for example,
using concentrated HBr, or BBrs.
[0022] The phenolic alkylations found in Flowsheets 2 and 3 and the bromine replacement
reaction of Flowsheet 2 each represent conventional nucleophilic displacement reactions.
These displacements are generally carried out in the presence of a base of sufficient
strength to convert the displacing phenol, alcohol or thiol to its salt, and in a
quantity at least sufficient to neutralize the by-product acid (HX
I, HBr). In those substrates which contain an aliphatic alcohol group [e.g., a compound
(IV) wherein Y
2 is H and Y
3 is OH], bases of sufficient strength to convert that group to the anion will generally
be used in an amount no more than sufficient to convert the more acidic phenol to
the salt. When either of the reactants contains a group of acidity similar to or greater
than that of the nucleophilic displacing compound, such potentially interfering groups
are best introduced in protected form (e.g., a heteroaromatic phenolic group as methoxy
or benzyloxy, a carboxy group as methyl or benzyl ester, removable by hydrolysis or
hydrogenolysis according to methods detailed elsewhere herein). The present nucleophilic
displacements are carried out in a reaction-inert solvent, preferably one which is
much less acidic than the displacing phenol, alcohol or mercaptan. Most preferred
are polar, aprotic solvents such as dimethylformamide or acetone, usually with a molar
excess of the more readily available of the two reactants. Temperature is not critical,
e.g., about 10-70 C is usually satisfactory with ambient temperature most convenient.
In one preferred variant, the phenol, alcohol or mercaptan is irreversibly converted
to the anion with a base such as sodium hydride. Other preferred variants employ K
2C0
3 as base in the presence of Nal, or Cs
2CO
3 as base in the presence of Csl.
[0023] The formylation of Flowsheet 2 represents a conventional condensation type reaction
of a ketone with an alkyl formate. This reaction is generally in an aprotic reaction-inert
solvent such as toluene in the presence of a strong base such as sodium hydride at
moderate temperatures (e.g., 0-70 C, conveniently at ambient temperature). The subsequent
conversion to the diazo compound is conveniently accomplished with tosyl azide as
the reagent, a reaction generally carried out at low temperature (e.g., about -10
to -60 C) in the presence of molar excess of a tertiary amine (e.g., triethylamine)
in a reaction-inert solvent such as CH
2Cl
2. In turn, the diazo compound is reacted with an appropriate alcohol or mercaptan
in the presence of a catalytic amount of rhodium (II) diacetate dimer to form the
desired ether or thioether. The latter transformation is generally carried out in
an anhydrous reaction-inert solvent such as toluene at somewhat elevated temperature,
e.g., about 50-100
* C Substituent alcohol or carboxy groups which are not intended to react are preferably
protected in this transformation, as in the case of the nucleophilic displacement
reactions discussed above.
[0024] The "reduction" reactions of Flowsheet 3 require the reduction of a ketone to a secondary
alcohol, for which a number of selective reagents are available. Where no other LiAIH
4 reducible groups (such as carboxy, methoxycarbonyl) are present, that reagent is
well suited for this purpose. On the other hand, NaBH
4 is preferred as the reducing agent when such reducible groups are present. In either
case, these hydride reductions are generally carried out in a reaction-inert solvent
(such as tetrahydrofuran in the case of LiAIH
4, methanol or a combination of methanol and tetrahydrofuran in the case of NaBH
4). In either case, temperature is not critical, about 0 to 50° C being generally satisfactory
and ambient temperature preferred. The present reduction step offers the potential
of producing a mixture of cis- and trans-isomers [as illustrated in the formulas (II)
and (III)] and in the present hydride reduction, that is the result which is generally
observed. If one or the other of these isomers is particularly desired, one can usually
find a reduction method and set of conditions which will favor the desired isomer.
For example, NaBH
4 reduction in the presence of cerium chloride will generally strongly favor the cis-isomer.
Catalytic hydrogenation is also a generally useful reduction method, generally carried
out under conditions which are somewhat more vigorous than those described above (e.g.,
more prolonged time, higher catalyst level, higher temperature and/or higher pressure).
Pd/C catalyst tends to particularly favor formation of cis-isomer. However, by variation
of the catalyst and conditions, it will be possible to modify or even reverse that
tendency. Where both cis- and trans-isomers form in the present reduction, they are
generally separable by standard chemical methods (e.g., selective or fractional crystallization,
chromatography, and so forth).
[0025] Those ketone compounds of the formula (I) wherein Y and Y' form a carbonyl group,
and of the formula (IV) in the first alternative, contain an asymmetric carbon at
the alpha-position which is adjacent to the carbonyl group, and therefore are racemic
compounds capable of resolution into optically active enantiomers, e.g., by conversion
of the racemate into diastereomeric salts with an optically active acid, which are
generally separable by a fractional crystallization process. Alternatively, if the
substrate contains a carboxy group, separable diastereomeric salts are formed with
an optically active organic amine. Optical activity can also be induced by use of
' an optically active reagent in the step by which the asymmetric carbon is formed,
e.g., use of an optically active Wilkinson type catalyst, or a noble metal supported
on an optically active support, in the hydrogenation step. The optically active ketones
are also available by conventional reoxidation of an optically active alcohol of the
next paragraph, e.g., via the Jones oxidation.
[0026] The hydroxy compounds of the formula (I) and (IV) wherein Y (or V
2) is hydrogen and Y' (or V3) is OH contain two such asymmetric carbons--corresponding
to two racemates and four optically active compounds. One of these racemates is the
above noted cis-isomer, and the other the trans-isomer. Each of these racemates is
capable of resolution into a pair of enantiomers via diastereomeric salts, as detailed
in the preceding paragraph. It is preferred, however, to convert the racemic alcohol
to corresponding diastereomeric esters or urethanes formed with an optically active
acid or isocyanate. Such covalently bonded derivatives are generally subjectable to
a broader variety of separation methods (e.g., chromatography) than are diastereomeric
salts. Such diastereomeric esters are formed from the alcohol and the optically active
acid by standard methods, generally those involving activation of the acid, e.g.,
as the acid chloride, as a mixed anhydride with an alkyl chloroformate, or with a
dehydrative coupling agent such as dicyclohexylcarbodiimide. A preferred optically
active acid in the present case is N
alpha-(t-butoxy)tryptophan. Once the resulting diastereomeric esters are separated, e.g.,
by chromatographic methods, they are hydrolyzed by conventional methods, e.g., aqueous
acid or aqueous base, to obtain the enantiomeric, optically active alcohols.
[0027] The prodrug esters of the present invention are prepared by methods similar to those
used in the synthesis of esters in the preceding paragraph. Esters with alpha-amino
acids, including natural L-amino acids, will generally by prepared from the appropriate
amino acid in which the alpha-amino group, substituent NH
2 or NH groups (e.g., lysine, ornithine, arginine, histidine, tryptophan), hydroxy
groups (serine, homoserine, threonine, tyrosine), mercapto groups (cysteine) and substituent
carboxy groups (glutamic acid, aspartic acid) are in protected form (e.g., N-benzyloxycarbonyl,
O- and S-benzyl) generally removed by catalytic hydrogenation in a subsequent step.
Similarly, in the case of esters with primary or secondary amino substituents, the
acids will be coupled with amino groups protected. Such protection is, of course,
unnecessary with those acids containing tertiary amino substituents. Finally, the
carboxy substituted esters are most conveniently prepared from the cyclic anhydride:

[0028] Concerning the biological activity of the present compounds, it is known that arachidonic
acid is metabolized in mammals by means of two distinct pathways, one leading to prostaglandins
and thrombox- anes, the other to several oxidative products called leukotrienes, which
are designated by letter number combinations such as B4, C4 and D4. The first step
in this oxidative pathway is the oxidation of arachidonic acid under the influence
of 5-lipoxygenase enzyme, an enzyme which is generally inhibited by the compounds
(I) of the present invention, thus blocking the synthesis of all leukotrienes. That
in itself provides the mechanism sufficient for the utility of the present compounds
in the treatment or prevention of asthma (where LTC4 and LTD4 are understood to be
mediators), arthritis (where LTB4 is understood to be a mediator in inflammation),
psoriasis (where LTB4 is understood to be a mediator), ulcers (where LTC4 and LTD4
are understood to be mediators) and myocardial infarction (where LTB4 is understood
to be a mediator). For a review concerning leukotrienes, see Bailey et al., Ann. Reports
Med. Chem. 17, pp. 203-217 (1982).
[0029] The in vitro activity of the compounds of the formula (I) is tested as follows. RBL-1
cells, maintained in monolayer form are grown for 1 or 2 days in spinner culture in
Minimum Essential Medium (Eagle) with Earl's Salts plus 15% Fetal Bovine Serum supplemented
with antibiotic/antimycotic solution (GIBCO). The cells are washed 1 time with RPMI
1640 (GIBCO) and resuspended in RPMI 1640 plus 1 microM glutathione to a cell density
of 1 x 10
7 cells/ml. A volume of 0.5 ml of the cell suspension is incubated at 30° C with 0.001
ml of dimethylsulfoxide solution of drug for 10 minutes. The reaction is started by
a simultaneous addition of 0.005 ml (14C)-arachidonic acid in ethanol and 0.002 ml
A23187 in dimethylsulfoxide to give final concentrations of 5.0 and 7.6 microM, respectively.
After a 5 minute incubation at 30° C, the reaction is stopped by the addition of 0.27
ml acetonitrile/acetic acid (100/0.3) and the media is clarified by centrifugation.
Analysis of the product profile is made by a 0.2 ml injection of the clarified supernatant
into HPLC. The separation of radioactive products is effected on a radial PAX CN column
(5 mm I.D., Waters) with a solvent system of acetonitrile/H
20/acetic acid (0.1 %) with a linear acetonitrile gradient from 35% to 70% over 15
minutes at 1 mi/minute. Quantitation is accomplished with a Berthold Radioactivity
Monitor equipped with a built-in integrator and a 0.2 ml flow cell mixing 2.4 ml/minute
Omnifluor (NEN) with column effluent. Integration units for each product are calculated
as a percentage of total integration units, and then compared to the average control
levels. The results are expressed as "Percent of Control" and are plotted vs the log
of drug concentration. The IC
so values are estimated by graphical inspection.
[0030] To evaluate the compounds of the formula (I) in vivo, they are tested by the so-called
PAF lethality assay procedure:
Materials:
Mice: CDI males, all approximately the same weight (approximately 26 grams), 12 per
group.
Vehicle for oral drug dosing: EES (5% ethanol, 5% emulphor, 90% saline). Stored at
room temperature. Drugs: For routine screening at 50 mg/kg, 20 mg drug is dissolved
in 4 ml EES, using soni--4ion in a sonicator bath or grinding in a Ten Broeck grinder
to dissolve drug if necessary. If solubil: still a problem, the drug is used as a
suspension.
Vehicle for i.v. Injection: Saline with 2.5 mg/ml Bovine Serum Albumin (BSA, Sigma
#A4378) and 0.05 mg/ml Propranolol (Sigma #P0884). Prepared fresh daily and kept at
room temperature.
Platelet Activating Factor (PAF): A 10 microM stock solution is prepared by dissolving
1 mg PAF (Calbiochem #429460) in 0.18 ml ethanol. This is stored at -20 C and is diluted
in vehicle (see above) the day of use. The concentration of PAF used is calibrated
so that when injected at 0.1 ml/10 grams body weight, it will kill approximately 80%
of untreated controls. This is usually about 0.028 g/kg (a 1 to 2034 dilution from
stock). The solution is prepared in glass containers and is used with glass syringes
to minimize surface adhesion by the PAF. It is kept at room temperature.
Positive Control: Phenidone is used at 25 mg/kg (its approximate ED 50).
Method:
45 minutes before PAF injection, mice are treated orally with drug using 0.1 ml/10
grams body weight. 35 to 40 minutes later they are placed under a heat lamp to dilate
the caudal vein for PAF injection. PAF is injected i.v. at 0.1 ml/10 grams body weight,
and death follows usually within 30 minutes, rarely after 60 minutes. Results are
expressed as percent mortality as compared to controls. Because the assay appears
to be sensitive to endogenous catecholamines (i.e., beta agonists protect the mice),
Propranolol is used to overcome this potential problem. It also helps if the mice
are acclimated to the room before testing, and if room noise and temperature are kept
moderate and constant. The heat lamp distance should be calibrated so as to permit
vasodilation without visible stress to the mice. Fasting the mice should be avoided.
Variations:
1. The time for oral dosing can be changed.
2. Intravenous drug dosing is possible by coinjecting the drug with PAF in the same
volume and vehicle as described above. For coinjection, PAF is prepared at twice the
desired concentration in saline with BSA and Propranolol as above, and the drug is
prepared at twice the desired concentration in the same vehicle. The two preparations
are mixed in equal volumes immediately before injection.
[0031] Compounds of the present invention are tested for utility against stroke in gerbils
according to the method of Gaudet et al., Stroke, vol. 11, pp. 648-652 (1980).
[0032] For use in the prevention or treatment of asthma, arthritis, psoriasis and gastrointestinal
ulcers in a mammal, including man, a compound of the formula (I) is given in a 5-lipoxygenase
inhibiting amount of about 0.5-50 mg/kg/day, in single or divided daily doses. A more
preferred dosage range is 2-20 mg/kg/day, although in particular cases, at the discretion
of the attending physician, doses outside the broader range may be required. The preferred
route of administration is generally oral, but parenteral administration (e.g., intramuscular,
intravenous, intradermal) will be preferred in special cases, e.g., where oral absorption
is impaired as by disease, or the patient is unable to swallow.
[0033] The compounds of the present invention are generally administered in the form of
pharmaceutical compositions comprising at least one of the compounds of the formula
(I), together with a pharmaceutically acceptable vehicle or diluent. Such compositions
are generally formulated in a conventional manner utilizing solid or liquid vehicles
or diluents as appropriate to the mode of desired administration: for oral administration,
in the form of tablets, hard or soft gelatin capsules, suspensions, granules, powders
and the like; and, for parenteral administration, in the form of injectable solutions
or suspensions, and the like.
[0034] The present invention is illustrated by the following examples, but is not limited
to the details thereof.
EXAMPLE 1
6-Benzyloxy-3-(3-pyridyloxy)-4-chromanone
[0035] To a solution of 3-hydroxypyridine (8.56 g, 0.090 mol) in 300 ml of dimethylformamide
was added NaH (60% in oil, 3.6 g, 0.090 mol). After stirring 0.5 hour, 6-benzyloxy-3-bromo-4-chromanone
(30.0 g., 0.090 mol) was added in one portion. After stirring for 1 hour, the reaction
mixture was poured into 1 liter of water and extracted 3 x 250 ml of ethyl acetate.
The organic layers were combined, washed 1 x 100 ml H
20, 1 x 100 ml 10% LiCI and 1 x 100 ml brine, dried (Na2SO4) and stripped to yield
40 g of crude title product, which was chromatographed on silica gel using 1:4 ethyl
acetate:CH
2CI
2 as eluant to yield 1.13 g of purified title product as an off-white powder; mp 133-134°C
A portion (290 mg) was recrystallized from isopropyl ether to yield 240 mg of white
powder.
EXAMPLE 2
cis-6-Benzyloxy-3-(3-pyridyloxy)-4-chromanol
[0036] Title product of the preceding Example (150 mg, 0.432 mmol) was dissolved in 2.5
ml of tetrahydrofuran and 4.0 ml of methanol and cooled to 0-5 °C under N
2. NaBH
4 (18 mg, 0.475 mmol) was added in one portion and, after 40 minutes at 0-5 °C, the
mixture warmed to ambient temperature, concentrated in vacuo, diluted with 70 ml ethyl
acetate, washed twice with water and once with brine, dried (Na
2SO
4), stripped in vacuo and the residue recrystallized from hot isopropyl ether to yield
105 mg of present title product as an off-white powder; mp 124-125 C;
1H-NMR (CDCl
3) includes delta (ppm) 5.03 (s, 2H). HRMS 349.1174, calcd. 349.1315. Anal. C 71.77,
H 5.42, N 3.88; calcd. C 72.18, H 5.48, N 4.01.
EXAMPLE 3
cis-3-(3-Pyridyloxy)-4,6-chromandiol
[0037] Title product of the preceding Example (6.94 g, 19.9 mmol) in 80 ml of tetrahydrofuran
and 160 ml of methanol was hydrogenated over 2.5 g of 10% Pd/C (50% water wet) at
50 psig for 20 hours. Catalyst was recovered by filtration over diatomaceous earth.
The filtrate was stripped in vacuo and the residue chromatographed on silica gel gradiently
eluted with 1:20 to 1:10 CH
3OH:CH
2Cl
2 to yield 3.15 g of purified title product; m/e 259.1 (M
+);
1H-NMR (DMSO-d
6) delta (ppm): 4.84 (m, 2H), 4.18 (m, 2H), 6.58-8.34 (7 aromatic H), 8.87 (br s, 1
H), 5.52 (d, 1 H).
EXAMPLE 4
cis-3-(3-Pyridyloxy)-6-(2-naphthyl)methoxy-4-chromanol
[0038] To title product of the preceding Example (500 mg, 1.93 mmol) and 2-(chloromethyl)naphthalene
(341 mg, 1.93 mmol) in 10 ml anhydrous dimethylformamide was added 98 mg (2.03 mmol)
of 50% NaH in oil. After stirring 17 hours, the mixture was poured into 200 ml H
20 and extracted 3x with ethyl acetate. The organic layers were combined, washed twice
with H
20 and once with brine, dried (Na
2SO
4), and stripped in vacuo. The residue was chromatographed on silica gel, gradiently
eluting with 1-2% CH
30H in CH
2CI
2, to yield 582 mg of title product as white crystals. Recrystallization from isopropyl
ether/CH
2Cl
2 gave 518 mg white plates; mp 156-157°C; HRMS 399.1466, calcd. 399.1417;
1H-NMR (CDCI
3) includes delta 5.20 ppm (s, 2H).
[0039] To prepare the hydrochloride salt, present title product (40 mg, 0.100 mmol) was
dissolved in 10 ml of ethyl acetate and 5 ml of CH
30H. 1N HCI in ether (0.150 ml, 0.150 mmol) was added and the mixture stirred 2 hours,
then stripped to yield 43 mg of HCI salt as an off-white powder; mp 112-114°C (degassing
at 75-80 C).
[0040] To prepare the dimethylaminoacetate ester of present title product, dimethylglycine
hydrochloride (74.3 mg, 0.532 mmol), 4-dimethylaminopyridine (0.065 ml, 0.532 mmol)
and dicyclohexylcarbodiimide (110 mg, 0.532 mmol) were added sequentially to a solution
of free base (170 mg, 0.426 mmol) in 20 ml of CH
2CI
2.
[0041] After 44 hours, dicyclohexylurea was recovered by filtration, the filtrate stripped
in vacuo, and the oily residue chromatographed on silica gel using gradient elution
with 1:19 to 1:9 CH
3OH:ethyl acetate to yield ester free base as a clear oil. The latter was dissolved
in 6 ml ether and 2 ml ethyl acetate. 1 N HCI in ether (0.945 ml) was added. After
stirring for 1 hour, the mixture was stripped to yield the dimethylaminoacetate ester
of title product as a dihydrochloride salt; HRMS 484.2016, calcd. for free base, 484.1999;
Anal. C 58.37, H 5.74, N 4.79; calcd. C 58.68, H 5.77, N 4.72.
EXAMPLES 5-9
[0042] By the method of the preceding Example, the title product of Example 3 and the indicated
reagent were converted to the following additional compounds, having properties as
indicated:
5. 1-Phenylethyl bromide produces cis-6-(1-phenylethoxy)-3-(3-pyridyloxy)-4-chromanol;
mp 115-118°C; HRMS 363.1422, calcd. 363.1471; 1H-NMR (300 MHz, CDCl3) includes delta 5.03 (s, 2H).
6. Benzyhydryl bromide produces cis-6-(diphenylmethoxy)-3-(3-pyridyloxy)-4-chromanol;
mp 145-146° ; HRMS 425.1632, calcd. 425.1628. Anal. C 75.24, H 5.52, N 3.19, calcd.
C 75.15, H 5.53, N 3.25. Hydrochloride salt; mp 152-155° C; 1H-NMR (300 MHz, CDCl3) includes delta 5.11 (s, 1H) and 4.97 (s, 1H).
7. 1-(2-Naphthyl)ethyl bromide produces diasteromeric cis-6-[1-(2-naphthyl)ethoxy]-3-(3-pyridyloxy)-4-chromanols;
mp 158-159°C; HRMS 413.1579, calcd. 413.1628; 1H-NMR (300 MHz, CDCl3) includes delta 1.68 (d, 3H, J = 6.4 Hz); and mp 122-124°C; HRMS 413.1770, calcd.
413.1628; 1H-NMR (300 MHz, CDCl3) includes delta 1.68 (d, 3H, J = 6.4 Hz).
8. (6-Fluoro-2-naphthyl)methyl bromide produces cis-6-[(6-fluoro-2-naphthyl)methoxy]-3-(3-pyridyloxy)-4-chromanol;
mp 141-142° C; HRMS 418.1483, calcd. 418.1454; Anal. C 71.67, H 4.67, N 3.21, calcd.
C 71.93, H 4.83, N 3.36.
9. (6-Methoxy-2-naphthyl)methyl bromide produces cis-6-[(6-methoxy-2-naphthyl)methoxy]-3-(3-pyridyloxy)-4-chromanol;
mp 168-169°C; HRMS 429.1533, calcd. 429.1577; Anal. C 72.03, H 5.25, N 3.19, calcd.
C 72.70, H 5.40, N 3.26.
EXAMPLE 10
cis-(-)- and cis-(+)-Nalpha-(t-Butoxycarbonyl)-L-tryptophan Esters of 3-(3-Pyridyloxy)-6-(2-naphthyl)methoxy-4-
chromanol
[0043] Title product of Example 4 (2.32 g, 5.8 mmol) was combined with CH
2Cl
2 (35 ml) in a flame dried flask. N
alpha-(t-butoxycarbonyl)-L-tryptophan (1.95 g, 6.7 mmol) was added, followed by dimethylaminopyridine
(0.818 g, 6.7 mmol) and finally dicyclohexylcarbodiimide (1.38 g, 6.7 mmol). The mixture
was stirred for 18 hours, dicyclohexyl urea recovered by filtration, and the filtrate
chromatographed directly on silica gel using 63:63:4 CHCl
3:hexane:2-propanol as eluant to separate the less polar and more polar diastereomeric
title products. The less polar product, 1.98 g, was rechromatographed in the same
system to yield 1.56 g of purified cis-(-)-title product,

= -38.46 (CHCI
3). Minor more polar product fractions from the second column were combined with more
polar product fractions of the first column and stripped to yield 2.14 g of cis-(+)-title
product;

= +37.12°(CHCl
3).
EXAMPLE 11
cis-( + )-6-(2-Naphthyl)methoxy-3-(3-pyridyloxy)-4-chromanol
[0044] The cis-(-)title ester of the preceding Example (1.75 g, 2.6 mmol) was combined with
35 ml of methanol and 20 ml of 1N NaOH and the mixture heated at reflux for
15 minutes, cooled, neutralized with 2N HCI, stripped of methanol, and the resulting
white solids recovered by filtration and recrystallized from toluene to yield 639
mg of present title product; mp 180-181 °C; HRMS 399.1436, calcd. 399.1471;

= + 66.4° (CHCl
3); Anal. C 74.98, H 5.11, N 3.51, calcd. C 75.17, H 5.30, N 3.51.
[0045] The corresponding hydrochloride salt was formed by dissolving 202 mg of this product
in 10 ml tetrahydrofuran and adding 0.51 ml of 1 N HCI in ether (1 equivalent), concentrating
to dryness, three times adding toluene and restripping, and triturating the residue
with ethyl acetate: 185 mg; mp 85°C (degassing), 190° (dec); HRMS 399.1436, calcd.
399.1471.
EXAMPLE 12
cis-(-)-6-(2-Naphthyl)methoxy-3-(3-pyridyloxy)-4-chromanol
[0046] By the method of the preceding Example, the cis-(+)-title product of Example 10 (2.14
g, 3.2 mmol) was converted to 848 mg of present title product; mp 180-181 C;

= -65.2° (CHCl
3); Anal. C 74.78, H 5.13, N 3.60, calcd. C 75.17, H 5.30, N 3.51.
[0047] A portion (203 mg) was converted to 186 mg of hydrochloride salt in like manner;
mp 85°C (degasses), 190°C (dec).
EXAMPLE 13
6-Benzyloxy-3-(2-methyl-3-pyridyloxy)-4-chromanone
[0048] By the method of Example 1, 3-hydroxy-2-methylpyridine was converted to present title
product; IR-(CHCl
3) 1697, 1486 cm
-1;
1H-NMR (300 MH
3, CDCl
3) includes delta 2.48 (s, 3H) and 4.6 (m, 2H).
EXAMPLE 14
cis-6-Benzyloxy-3-(2-methyl-3-pyridyloxy)-4-chromanol
[0049] By the method of Example 2, the title product of the preceding Example was converted
to present title product; mp 133-134°C; HRMS 363.1410 calcd. 363.1471; Anal. C 72.23,
H 5.72, N 3.81, calcd. C 72.71, H 5.82, N 3.85.
[0050] By the method of Example 3, this compound is converted to 6-hydroxy-3-(2-methyl-3-(2-methyl-3-pyridyloxy)-4-chromanol,
which in turn is converted to the corresponding 6-(substituted)oxy analogs of Examples
4-9 by the methods of those Examples.
EXAMPLE 15
cis-7-Benzyloxy-3-(3-pyridyloxy) -4-chromanol
[0051] By the method of Example 1, 7-benzyloxy-3-bromo-4-chromanone was converted to 7-benzyloxy-3-(3-pyridyloxy)-4-chromanone,
which, by the method of Example 2 was converted to present title product, mp 73-75
C; HRMS 349.1302, calcd. 349.1315;
1H-NMR (300 MHz, CDCl
3) includes delta 5.04 (s, 2H).
EXAMPLE 16
cis-3-(3-Pyridyloxy)-7-(2-naphthyl)methoxy-4-chromanol
[0052] By the method of Example 3, the title product of the preceding Example was converted
to cis-3-(3-pyridyloxy)-4,7-chromandiol, which, by the method of Example 4 was converted
to present title product; mp 155-158 C; HRMS 399.1484, calcd. 399.1471, Anal. C 74.57,
H 5.24, N 3.49, calcd. C 75.18, H 5.30, N 3.51.
[0053] By the further methods of Example 4, present title product was further converted
to its N,N-dimethylglycine ester, dihydrochloride salt; mp 95 C (dec); HRMS 484.2016,
calcd. 484.1999; Anal. C 58.37, H 5.74, N 4.79, calcd. C 58.68, H 5.77, N 4.72.
EXAMPLE 17
6-Benzyloxy-3-(3-(methoxycarbonyl)benzylidene)-4-chromanone
[0054] A mixture of 17 g of 6-benzyloxy-4-chromanone, 11.3 g of 3-carbomethoxybenzaldehyde,
14.4 g of pyrrolidine, 100 ml of tetrahydrofuran and 300 ml of methanol was stirred
at room temperature overnight. The volatiles were evaporated in vacuo to afford the
crude product, which was purified by column chromatography on silica gel eluting with
dichloromethane. The product fractions were combined and concentrated to an oil which
crystallized upon trituration with methanol to give 17.2 g of title product, mp 109-112°
C.
EXAMPLE 18
6-Hydroxy-3-(3-methoxycarbonylbenzyl)-4-chromanone
[0055] A mixture of 17 g of the product of the preceding Example, 1.7 g of 10% Pd/C catalyst,
200 ml of tetrahydrofuran and 200 ml of methanol was hydrogenated in a Parr shaker
at 40 psig for 3 hours. The catalyst was removed by filtration and the volatiles were
evaporated in vacuo to give 10.6 g of title product.
1H-NMR(acetone-d
6)delta (ppm): 2.65-3.30 (m, 3H), 3.80 (s, 3H), 472 (dd, J=4Hz, J=8Hz, 2H), 6.80-8.30
(m, 7H).
EXAMPLE 19
cis- and trans-3-(3-Methoxycarbonylbenzyl)chroman-4,6-diol
[0056] By the methods of Example 39, the product of the preceding Example was converted
to present chromatographed title products in about the same yields. This cis-isomer,
mp 135-137°C, is less polar and the trans-isomer, mp 158-160°C, is more polar; tlc
(7:3 CH
2Cl
2:ether) Rf 0.25 and 0.20, respectively.
EXAMPLE 20
cis-3-(3-Methoxycarbonylbenzyl)-6-(2-naphthyl)methoxy-4-chromanol
[0057] By the method of Example 4, using 3% ethyl acetate in CH
2CI
2 as eluant in the chromatography, cis- title product of the preceding Example (296
mg, 0.942 mmol) was converted to 311 mg of present title product; HRMS 454.2 (M
+), 141.1 (base);
1H-NMR (300 MHz, CDCI
3) includes delta 3.91 (s, 3H), 5.13 (s, 2H).
EXAMPLE 21
cis-3-(3-Carboxybenzyl)-6-(2-naphthyl)methoxy-4-chromanol
[0058] To a solution of title product of the preceding Example (302 mg, 0.664 mmol) in 10
ml of methanol was added 5 ml of 1 N NaOH. After 45 minutes of reflux, the methanol
was removed in vacuo. The residue was diluted with water, the pH brought to 3 with
1N HCI, extracted 2x ethyl acetate, and the organic layer separated. The latter was
washed 1x brine, dried (Na
2SO
4), concentrated to a volume of 10 ml, and allowed to crystallize at room temperature.
Filtration gave 172 mg present title product, mp 183-184°C;
1H-NMR (300 MHz, DMSO-d
6) includes delta 5.18 (s, 2H); Anal. C 75.93, H 5.46, calcd. C 76.34, H 5.49.
EXAMPLE 22
6-Methoxy-3-(3-pyridyl) methylene-4-chromanone
[0059] To a 25°C mixture of 20.0 g (0.112 mol) of 6-methoxy-4-chromanone and 18.09 g (0.169
mol) of 3-pyridinecarbaldehyde in 100 ml of methanol was added 14.1 ml (0.169 mol)
of pyrrolidine. The resultant solution was allowed to stir 60 hours at 25°C, cooled
to 0°C and filtered to yield 17.07 g (57%) of the title compound, mp 127-131 C; MS
(m/e) 267 (M
+), 238, 161, 150 (100%), 135 and 107. IR (CHCl
3) 1671 (C=0), 1614, 1589 and 1566 cm
-1. 'H-NMR (CDCl
3) delta (ppm): 3.79 (s, OCH
3), 5.23 (d, J=1.5 Hz, CH
2), 6.86 (d, J=8 Hz, C-8 H), 7.06 (dd, J=8, 2 Hz, C-7 H), 7.37 (d, J=1.5 Hz, vinyl
H), 7.36, 7.58, 7.75, 8.52 and 8.57 (multiplets, 5 ArH). Anal. C 71.72, H 4.85, N
5.16, calcd. C 71.90, H 4.90, N 5.24.
EXAMPLE 23
6-Methoxy-3-(3-pyridylmethyl)-4-chromanone
[0060] A mixture of 25.2 g (94.4 mmol) of the title product of the preceding Example and
2 g of 5% Pd/C/50% H
20 in 1 liter ethyl acetate was hydrogenated at 35 psig hydrogen for 18 hours. The
reaction was filtered through diatomaceous earth with ethyl acetate wash, and the
combined filtrate and wash evaporated to an oil. Trituration of this oil with diisopropyl
ether gave the title compound as crystals, mp 82-84°C. MS (m/e) 269 (M
+), 252, 177, 150 (100%), 135, 118 and 107. IR (CHCI
a) 1685 (C=O), 1618 and 1578 cm
-1.
1H-NMR (CDCI
3) delta (ppm): 2.71 (dd, J=15, 10 Hz, 1 CH
2Ar), 2.86 (m, CH), 3.19 (dd, J=15, 6 Hz, 1 CH
2Ar), 3.75 (s, OCH
3), 4.07 (dd, J = 11, 8 Hz, 1 CH
20) , 4.30 (dd, J = 11, 6 Hz, 1 CH
2O), 6.82 (d, J = 9 Hz, C-8 H), 7.03 (dd, J=9, 2 Hz, C-7 H), 7.10 (dd, J=7. 7 Hz, C-5
PyrH), 7.27 (d, J = 2 Hz, C-5 H), 7.53 (d, J=7 Hz, C-4 PyrH) and 8.45 (m, 2 PyrH).
Anal. C 71.31, H 5.58, N 5.15, calcd. C 71.13, H 5.57, N 5.12.
EXAMPLE 24
6-Hydroxy-3-(3-pyridylmethyl)-4-chromanone
[0061] A mixture of 13.75 g (51.1 mmol) of the title product of the preceding Example, 46
ml of concentrated hydrobromic acid and 47 ml of acetic acid was heated at reflux
for 10 hours, and then stirred 12 hours at 25° C. The reaction was poured into 470
ml of ice and water and the pH adjusted to 7.5-8 with solid sodium bicarbonate. The
precipitate formed was stirred 0.5 hours, filtered, washed with water and dried in
vacuo to yield 11.79 g (90%) of the title compound, mp 163-166°C; MS (m/e) 255 (M
+, 100%). 241, 163, 136, 120 and 108. IR(KBr) 1687 (C=O), 1625, 1598 and 1582 cm
-1.
1H-NMR (DMSO-d
6) delta (ppm): 2.69 (dd, J = 11, 17 Hz, 1 CH
2Ar), 3.10 (m, CH and 1 CH
2Ar), 4.11 (dd, J = 11, 11 Hz, 1 OCH
2), 4.27 (dd, J = 11, 5 Hz, 1 OCH
2), 6.85 (d, J = 8 Hz, C-8H), 6.98 (dd, J = 8, 2 Hz, C-7H), 7.07 (d, J = 2 Hz, C-5H),
7.31 (dd, J = 9, 8 Hz, C-5 PyrH), 7.67 (d, J = 8 Hz, C-4 PyrH), 8.42 (m, 2 PyrH) and
9.48 (s, OH); Anal. C 69.39, H 5.08, N 5.37, calcd. (¼ H
20) C 69.35, H 5.24, N 5.39.
EXAMPLE 25
cis-3-(3-Pyridyl)methylchroman-4,6-diol
[0062] A mixture of the title product of the preceding Example (6.0 g, 0.023 mol) and cerium
chloride heptahydrate (CeCl
3 7H
20; 5.25 g, 0.0141 mol) in methanol (125 ml) was cooled to 0-5°C and sodium borohydride
(0.445 g, 0.0117 mol) was added in three portions. The reaction was stirred at room
temperature for 0.5 hours. Methanol was then removed in vacuo and the foamy residue
was treated with saturated NH
4Cl solution, followed by extraction with ethyl acetate. The organic layer was dried
over MgSO
4 and concentrated in vacuo to a foam. The foam was treated with toluene and then pumped
under high vacuum for several hours. This was repeated two more times to give present
title product (5.7 g, 94%). MS (m/e) 257 (M
+), 137, 120 and 101.
1H-NMR(DMSO-d
6) after D
2O exchange includes 4.22 (d, J=2Hz, cis isomer CHOD) and 4.17 (d, J = 4Hz, trans isomer
CHOD). This assay indicated about 4% contamination with the trans-isomer.
EXAMPLE 26
cis-6-(Diphenylmethoxy)-3-(3-pyridyloxy)-4-chromanol
[0063] To a solution of title product of the preceding Example (250 mg, 0.972 mmol) in 5
ml anhydrous dimethylformamide was added benzhydryl bromide (264 mg, 1.07 mmol). Sodium
hydride (60% oil dispersion; 41 mg, 1.02 mmol was added in one portion, and the reaction
stirred 16 hours, then diluted into 150 ml H
20 and extracted 3x with ethyl acetate. The organic layers were combined, washed 2x
H
20 and 1x brine, dried (Na
2SO
4), stripped to 0.50 g brown oil, and flash chromatographed on 90 g of silica gel gradiently
eluted with 2-5% CH
30H in CH
2Cl
2 to yield 268 mg of title product, which was crystallized from isopropyl ether/CH
2Cl
2 to yield 103 mg of purified title product; mp 169-170° C; HRMS 423.1834, calcd. 423.1836;
Anal. C 79.07, H 5.64, N 3.35, calcd. C 79.40, H 5.95, N 3.31.
EXAMPLE 27
3-(3-Pyridylmethyl)-6-[1-(2-quinolyl)ethoxy]-4-chromanone
[0064] A mixture of title product of Example 24 (1.00 g, 3.92 mmol), 1-(2-quinolyl)ethyl
methanesulfonate (1.08 g, 4.30 mmol), acetone (4.1 ml) and finely ground, anhydrous
K
2CO
3 (1.68 g, 12.2 mmol) was heated at 80°C for 17 hours. The resulting solution was cooled,
stripped of solvent and the residue taken into 250 ml H
20 and 200 ml CH
2CI
2. The aqueous layer was extracted 2x 200 ml fresh CH
2Cl
2, and the organic layers combined, dried (MgSO
4), stripped of solvent and flash chromatographed on silica gel using ethyl acetate
as eluant to yield 521 mg of present title product as an oil; MS 410 (M 156 (base);
HRMS 410.1643; IR (CHCl
3) 2966, 1686, 1484, 1284, 1074, 828 cm
-1.
EXAMPLE 28
cis- and trans-3-(3-Pyridylmethyl)-6-[1-(2-quinolyl)ethoxy]-4-chromanol
[0065] To a solution of title product of the preceding Example (456 mg, 1.11 mmol) in 5.6
ml of CH
3OH under N
2 at 0-5°C was added NaBH
4 (46 mg, 1.22 mmol) in one portion. The stirred mixture was slowly warmed to room
temperature and stirred for 2 hours, then the solvent stripped in vacuo, the residue
taken up in 50 ml of CH
2Cl
2 and 50 ml saturated NaCI, the layers separated and the aqueous layer extracted 2x
50 ml CH
2CI
2. The combined organic layers were dried (MgSO
4), stripped to an oil and chromatographed on silica gel using 1:1:1:7 ethyl acetate:isopropanol:hexane:CH
2CI
2 as eluant to yield 129 mg of the cis-isomer of present title product as a white solid
and 41 mg of the trans-isomer as an oil. Cis-isomer; mp softens at 67° C; MS 412 (M
+), 156 (base); IR (CHCI
3) 2954, 1491, 1258, 1073, 778 cm
-1. Trans-isomer: MS 412 (M
+), 156 (base);
1H-NMR (300 MHz, DMSO-d
6) delta (ppm) 8.24-8.50 (m, 2H), 8.17 (d,J=8.9Hz, 1H), 8.10 (d, J =
8.
7Hz, 1 H), 7.76 (d, J =
8.
9Hz, 1 H), 7.69 (t, J = 6.9Hz, 1 H), 7.60 (d, J =
8.8Hz, 1 H), 7.45-7.56 (m, 2H), 7.15-7.30 (m, 1 H), 7.00 (d, J = 2.4Hz, 1 H), 6.75
(dd, J = 8.8, 2.4Hz, 1 H), 6.62 (dd, J =
7.
7, 4.8Hz, 1 H), 5.60 (q, J = 6.6Hz, 1 H), 4.36 (d, J = 5.6Hz, 1 H), 4.05 (dd, J = 10.8,
4.2Hz, 1 H), 3.76 (dd, J = 10.8, 6.6Hz, 1 H), 2.70 (dd, J = 13.2, 8.4Hz, 1 H), 2.46
(dd, J = 13.2, 9.0Hz, 1 H), 2.04-2.19 (m, 1 H) , 1.71 (d, J = 6.6Hz, 1 H).
EXAMPLE 29
cis-3-(3-Pyridyloxy)-6-[1-(2-quinolyl)ethoxy]-4-chromanol
[0066] By the method of Example 4, the title product of Example 3 (270 mg, 1.04 mmol) and
1-(2-quinolyl)-ethyl methanesulfonate (394 mg, 1.57 mmol) were converted to present
title product, purified by chromatography on silica gel column using 3% CH
3OH in ether as eluant, to yield purified title product as an approximately 1:1 mixture
of diastereoisomers; mp 75-83°C; MS 414 (M
+), 156 (100%): Anal. C 69.68, H 5.42, N 6.38, calcd. C 69.43, H 5.59, N 6.48; IR (CHCl
3) 2956, 1575, 1490, 1256, 1073, 830 cm
-1.
EXAMPLE 30
6-Benzyloxy-3-(4-methoxyphenoxy)-4-chromanone
[0067] A solution of 76 g of 3-diazo-6-benzyloxy-4-chromanone and 76 g of p-methoxyphenol
in 450 ml of toluene was heated to 110°C in an oil bath. Rhodium (II) acetate dimer
(225-mg) was added in one portion. After nitrogen evolution ceased (5 minutes), the
reaction was allowed to cool to room temperature, diluted with ethyl acetate and washed
with 10% sodium hydroxide to remove excess phenol. The organic layer was dried over
sodium sulfate and evaporated in vacuo to give the crude product, which was purified
by column chromatography on silica gel eluting with dichloromethane to give 5.5 g
of present title product; mp 98-100°C;
1H-NMR (CDCl
3) delta (ppm): 3.85 (s, 3H), 4.45-4.65 (m, 2H), 5.0-5.2 (m, 3H), 6.5-7.6 (m, 12H).
EXAMPLE 31
cis-3-(4-Methoxyphenoxy)-4,6-chromandiol
[0068] By the method of Example 3, the product of the preceding Example (5.5 g) was converted
to present title product, 2.3 g, mp 187-189
- C; HRMS 288.0989, calcd. 288.0998.
EXAMPLE 32
cis-3-(4-Methoxyphenoxy)-6-[1-(2-quinolyl)ethoxy]-4-chromanol
[0069] By the method of Example 29, using 1:2 ethyl acetate:hexane as chromatography eluant,
product of the preceding Example (452 mg, 1.57 mmol) was converted to 507 mg of present
title product; mp 58-61 C; MS 443 (M
+, base); IR (CHCl
3) 3561, 2930, 1603, 1492, 1240, 1032, 829 cm-
1; Anal. C 69.68, H 5.42, N 6.38, calcd. C 69.43, H 5.59, N 6.48.
[0070] By the further methods of Example 4, present title product was further converted
to its N,N-dimethylglycine ester, dihydrochloride salt; mp 81-85 C; MS 528 (M
+), 156 (base); IR (CHCl
3) 2950, 1646, 1492, 1166, 1019, 654 cm
-1.
EXAMPLE 33
7-Methoxy-3-(3-pyridyl) methylene-4-chromanone
[0071] By the method of Example 22, 7-methoxy-4-chromanone (10 g, 56 mmol) and 3-pyridinecarbaldehyde
(7.8 g, 73 mmol) were converted to present title product, isolated directly from the
reaction mixture by cooling to 0°C, 11.9 g; mp 176-178°C; MS 267 (M
+, base peak). Anal. C. 71.94, H 4.93, N 5.05, calcd. C 71.90, H 4.90, N 5.24.
EXAMPLE 34
7-Methoxy-3-(3-pyridy(methyl)-4-chromanone
[0072] Title product of the preceding Example (12.85 g) in 300 ml CH
aOH was hydrogenated for 12 hours at 50 psig over 1.4 g of 10% Pd/C. Catalyst was recovered
by filtration. The filtrate was stripped to an oil from which title product was crystallized
by trituration with 200 ml of warm isopropyl ether, 9.89 g; mp 95-99°C; MS 269 (M
+), 122 (base); IR (CHCl
3) 2958, 1678, 1611, 1577, 1435, 1258, 837 cm
-1. Anal. C 70.94, H 5.54, N 5.06, calcd. C 71.13, H 5.57, N 5.12.
EXAMPLE 35
7-Hydroxy-3-(3-pyridylmethyl)-4-chromanone
[0073] By the method of Example 24, title product of the preceding Example (3.8 g) was converted
to present title product, 3.37 g; mp 181-190°C; Anal. C. 69.96, H 5.16, N 5.33, calcd.
for 0.25 H
20 C 69.35, H 5.24, N 5.39.
EXAMPLE 36
3-(3-Pyridylmethyl)-7-[1-(2-quinolyl)ethoxy]-4-chromanone
[0074] By the method of Example 29, using ether as chromatography eluant, title product
of the preceding Example (740 mg, 2.90 mmol) was converted to 650 mg of present title
product as a semi-solid; MS 410 (M
+), 156 (base); IR (CHCl
3) 2967, 1678, 1607, 1437, 1246, 1213, 829 cm
-1.
EXAMPLE 37
cis- and trans-3-(3-(Pyridylmethyl)-7-[1-(2-quinolyl)ethoxy]4-chromanol
[0075] By the method of Example 2, the title product of the preceding Example (1.095 g,
2.67 mmol) was reduced to a mixture of diasteromeric title products: Initial silica
gel chromatography using 5% CH
3OH in ether gave two white solids: 510 mg of a mixture of two diasteromeric cis-isomers;
mp 73°C (softens), 84° C (partial); MS 412 (M
+), 156 (base); IR (CHCl
3) 3592, 2955, 1618, 1498, 1073, 658 cm
-1; and 350 mg of a mixture of two diasteromeric trans-isomers.
[0076] The trans-diastereomers were dissolved in 30 ml of ether and 1 ml of CH
2Cl
2, concentrated to 10 ml, allowed to stand for 18 hours and 135 mg of trans-diastereomer
A recovered by filtration; mp 147-151 °C; MS 412 (M+), 156 (base); IR (CHCl
3) 3592, 2967, 1619, 1498, 1165, 1020, 660 cm-'. The filtrate was stripped and the
residue rechromatographed in like manner to yield 176 mg of trans-diastereomer B;
mp 73° (partial), 173°C; MS 412 (M
+), 156 (base); IR (CHCl
3) 3595, 2961, 1619, 1498, 1164, 1133, 659 cm-'.
EXAMPLE 38
7-(Diphenylmethoxy)-3-(3-pyridylmethyl)-4-chromanone
[0077] By the method of Example 4, using CH
2CI
2 and then 5% CH
30H in ether as eluants on chromatography, benzhydryl bromide (1.16 g, 4.69 mmol) and
title product of Example 35 (1.00 g, 3.92 mmol) were converted to 908 mg of methanol
triturated title product as a white solid; mp 45°C (partial), 100 C; MS 421 (M+),
167 (base); IR (CHCl
3) 2959, 1677, 1608, 1575, 1436, 1200 cm
-1.
EXAMPLE 39
cis- and trans-7-(Diphenylmethoxy)-3-(3-pyridylmethyl)-4-chromanol
[0078] By the method of Example 2, using gradient elution with 0-5% CH
30H in ether on chromatography, title product of the preceding Example (908 mg, 2.15
mmol) was converted to 441 mg of title cis-isomer, recrystallized from ether to yield
333 mg of further purified cis-isomer; mp 143-146°C; MS 423 (M+), 167 (base); IR (CHCI
3) 3590, 2953, 1617, 1495, 1162, 1114 cm
-1; and 251 mg of title trans-isomer, triturated with 1:1 ether:CH
2Cl
2 to yield 133 mg of further purified trans-isomer; mp 140-150 C; MS 423 (M
+), 167 (base).
EXAMPLE 40
6-Benzyloxy-3-(3-(methoxycarbonyl)benzylidene)-4-chromanone
[0079] A mixture of 17 g of 6-benzyloxy-4-chromanone, 11.3 g of 3-carbomethoxybenzaldehyde,
14.4 g of pyrrolidine, 100 ml of tetrahydrofuran and 300 ml of methanol was stirred
at room temperature overnight. The volatiles were evaporated in vacuo to afford the
crude product, which was purified by column chromatography on silica gel eluting with
dichloromethane. The product fractions were combined and concentrated to an oil which
crystallized upon trituration with methanol to give 17.2 g of title product, mp 109-112°C.
EXAMPLE 41
6-Hydroxy-3-(3-(methoxycarbonyl)benzyl)-4-chromanone
[0080] A mixture of 17 g of the product of the preceding Example, 1.7 g of 10% Pd/C catalyst,
200 ml of tetrahydrofuran and 200 ml of methanol was hydrogenated in a Parr shaker
at 40 psig for 3 hours. The catalyst was removed by filtration and the volatiles were
evaporated in vacuo to give 10.6 g of title product;
1H-NMR (acetone-d
6) delta (ppm): 2.65-3.30 (m, 3H), 3.80 (s, 3H), 4.2 (dd, J=4, J=8, 2H), 6.80-8.30
(m, 7H).
EXAMPLE 42
cis- and trans-3-(3-(Methoxycarbonyl)benzyl)chroman-4,6-diol
[0081] To a solution of 4.7 g of the title product of the preceding Example in 100 ml of
methanol was added 550 mg of sodium borohydride. The reaction was stirred at room
temperature for 1 hour, then quenched with water. The solvent was evaporated in vacuo
and the residue dissolved in ethyl acetate and washed with water. The ethyl acetate
layer was dried over sodium sulfate and evaporated in vacuo to afford the crude product
mixture. It was separated by column chromatography on silica gel, eluting with dichloromethane/ether,
yielding about 1 g each of the less polar cis-isomer, mp 135-137°C; and the more polar
trans-isomer, mp 158-160°C; tic (7:3 CH
2CI
2:ether) Rf 0.25 and 0.20, respectively.
EXAMPLE 43
cis-3-(3-Carboxybenzyl)-6-[1-(2-quinolyl)ethoxy]-4-chromanol
[0082] With resulting concurrent hydrolysis of the methyl ester, and using 5% CH
30H in ether as eluant on chromatography, the method of Example 29 was used to convert
the title product of the preceding Example (467 mg, 1.49 mmol) to 196 mg of present
title product; mp 70-73 °C (partial); MS 455 (M
+-1), 156 (base); IR (CHCl
3) 2923, 1672, 1490, 1262, 1195, 1076, 830 cm
-1.
PREPARATION 1
4-(2-Cyanoethoxy)anisole
[0083] 4-Methoxyphenol (248 g), KOH (5.6 g) and acrylonitrile (397 ml) were dissolved in
1 liter of t-butanol and heated with stirring at 75° C for 5 hours. The mixture was
then cooled to room temperature and stripped in vacuo to solid residue, which was
repulped in ether and insolubles recovered by filtration. The latter were taken up
in 2 liters of ethyl acetate, washed in sequence with 1 liter each of H
2O, saturated NaHCO
3 and saturated NaCl, dried over MgS0
4 and restripped to yield purified title product, 199.4 g, mp 62-64° C.
PREPARATION 2
6-Methoxy-4-chromanone
[0084] The title product of the preceding Example (199 g) was combined with 240 ml H
20 and 480 ml of concentrated HCI and heated at reflux overnight. The reaction mixture
was cooled to room temperature and solids recovered by filtration. The latter were
taken up in 2 liters of ethyl acetate, washed with 200 ml of H
20, dried over MgS0
4 and stripped in vacuo to yield intermediate 3-(4-methoxyphenoxy)propionic acid, 195
g, mp 105-107°C. The latter was added to 600 ml of hot, stirred polyphosphoric acid
maintained at 75°C and the mixture stirred for 2 hours. The temperature rose to a
maximum of 89°C over the first one- half hour, then fell to the 75°C bath temperature.
The reaction mixture was quenched into 3.2 liters of ice and water and extracted with
1.2 liters of ethyl acetate. The organic extract was extracted in sequence with 600
ml each of H
20, saturated NaHC0
3 and saturated NaCl, dried over MgSO
4 and stripped to 180 g of solids which were taken up in 400 ml CH
2Cl
2, treated with activated carbon and restripped to a like quantity of solids. The latter
were recrystallized from isopropyl ether to yield purified title product, 120 g, mp
46-48° C, identical with the commercial product.
PREPARATION 3
6-Hydroxy-4-chromanone
[0085] A solution of 36 g of the product of the preceding Preparation in 290 ml of acetic
acid and 290 ml of 48% hydrobromic acid was heated at reflux for 3 hours. The reaction
was cooled and stripped in vacuo to crude product which was diluted with water (6
liters), cooled to 0-5°C and title product recovered by filtration, 25.7 g (80%),
mp 133-136 C. Optionally, the product is further purified by chromatography on silica
gel using ethyl acetate/hexane as eluant.
[0086] By the same method, 7-methoxy-4-chromanone was converted to 7-hydroxy-4-chromanone.
PREPARATION 4
6-Benzyloxy-4-chromanone
[0087] A mixture of 25 g of the product of the preceding Preparation, 26.5 g of benzyl bromide
and 28 g of potassium carbonate in 150 ml of acetone was heated at reflux overnight.
The reaction was cooled and filtered to remove potassium carbonate. The filtrate was
evaporated and the residue was dissolved in ethyl acetate and washed with water. The
ethyl acetate layer was dried over sodium sulfate and evaporated in vacuo to obtain
the crude product, which was purified by recrystallization from methylene chloride/hexane
to give 29 g of title product, mp 107-108°C.
[0088] 1H-NMR (acetone-d
6) delta (ppm): 2.7 (t, 2H), 4.4 (t, 2H), 5.08 (s, 2H), 7.2-7.5 (m, 3H).
[0089] By the same method, 7-hydroxy-4-chromanone was converted to 7-benzyloxy-4-chromanone.
PREPARATION 5
3-Hydroxymethylene-6-benzyloxy-4-chromanone
[0090] To a solution of 172.5 g of the product of the preceding Preparation in 1.7 liters
of toluene containing 168 ml of ethyl formate and 3.5 ml of ethanol was added, in
portions, 66 g of 50% sodium hydride. The reaction was allowed to stir at room temperature
for 1 hour, then poured into 1.5 liters of ice and H
20, and acidified to pH 4 with dilute hydrochloric acid. The aqueous layer was extracted
with several portions of ethyl acetate. The organic layers were combined, dried over
sodium sulfate and evaporated in vacuo to give the crude product which was triturated
with hexane to remove hydride oil. The resultant product crystallized on standing,
mp 82-85 C.
PREPARATION 6
3-Diazo-6-benzyloxy-4-chromanone
[0091] To a -10°C solution of 35.3 g of title product of the preceding Preparation in 250
ml of dichloromethane containing 25.2 g of triethylamine was added dropwise a solution
of 24.4 g of tosyl azide in 100 ml of dichloromethane. After complete addition, the
reaction was allowed to warm to room temperature and stirred overnight. The reaction
mixture was washed with water, dried over sodium sulfate and evaporated in vacuo to
give the crude product, which was purified by column chromatography on silica gel
eluting with dichloromethane to give 21 g of product, mp 100-103°C.
[0092] 1H-NMR (CDCl
3) delta (ppm): 5.02 (d, J=4, 2H), 6.7-7.5 (m, 10H).
PREPARATION 7
6-Benzyloxy-3-bromo-4-chromanone
[0093] A slurry of title product of the preceding Preparation (50.0 g, 0.197 mol) in 2200
ml of ether was cooled to 0-5°C under N
2. Bromine (10.1 ml, 0.197 mol) was added dropwise over 15-20 minutes and the mixture
further stirred for 30 minutes at 0-5 C, then for 1 hour at ambient temperature. The
mixture was washed 2x 500 ml H
20 and 1 x 400 ml brine, dried (Na
2SO
4) and stripped to yield 66.2 g of title product which was chromatographed on silica
gel using gradient elution with 1:1 to 3:1 CH
2Cl
2:hexane to yield 42.0 g of present title product as a tan powder.
1H-NMR (CDCl
3) delta (ppm) includes 5.06 (s, 2H), 4.6 (m, 3H). m/e M + 334/332.
[0094] By the same method 7-benzyloxy-4-chromanone was converted to 7-benzyloxy-3-bromo-4-chromanone.